Concrete well strainer



Sept. 7 1926.

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1,598,974 J. P. LAWLOR ET AL CONCRETE WELL STRAINER Filed May 6 1925lllllll l dfi/7:5 'JMX ratented Sept. 7, 1926.

UNITED STATES coNcnmE WELL erasmus.

application mea my s, 1925.. semi No. 28,367.

This invention relates to a well strainerdesigned for use indeep orsliallow wells, and to the well in which it is used.`

It especially relates to a concrete construc- 6 tion in which aplurality of annular units areL superimposed to form a strainenwhich isplaced in a hole or well inthe water bearing. sand to rmit the entranceof water into the we l, therethrough, and at 10 the same time excludethe entrance of sands and gravels as fully as possible.

There are ,at present concrete strainers of various desi but each hascertain oints of weakness` w ,'ch will' be eliminate in a strainerdesigned las described herein. vIn strains-.1s as now rmade, orpatented, the sags or sections, are held in place, o ne upon the cher,by means o` cables or rods. In such riesig. the rin or sections aresometimes difficult to align vertically and may become distorted from adirect vertical position by uneven pressure of the sandand gravelsurrounding same, or by other outside forces. f l 5 AAlnother weaknessin present designs is foundl in the small amount of supporting areabetween sections. In such design when a number of sections are placedone upon the other the compressive strength of the supportinglsurface isexceeded, thereby causing a crus ing of the concrete or other materialused to hold the sections or rings alpart and defeating the purpose forwhich. t

ey 'are intended. l p l 4In the design shown herein the bearing surfacebetween the Asections` or rings is greatly increased by providingbearing surface on both the upper and lower steps of the male and femalejoint. l 40 Another common weakness is found in the ailurelto sodesignthe strainer as to permit, as far as possible, a straight line of iow ofwater from the water bearing sands through the strainer into the well.This feature is of paramount importance because after the strainer hasbeen placed in posi` tion in thewell it is advisable, if not absolutelynecessary, to wash out and agitate the sands so as to increase the flowof water into the well. This is usually accomplished by alternatelyapplying pressure and suction, to the' water inside ofthe well, therebysetting up a surging action and causing the water to pass in andoutthrough the strainer and the sands or gravel surrounding same. If thewater passing in and out through the strainer is required to flowthrough various turns and passages, as is the condition with strainersnow in use, before entering the water bearing sands upon which it is toact, its force and effectiveness upon the water bearing sand itself isgreatly decreased and it is diiiicult if not impossible to develop awell so that -it will yield the maximum quantity of'water. Furthermore,when the well hasl been completed and is be'ing pumped constantly,indirect courses or passages through` which the water must travel ingoing through the strainer causes a loss in headby added friction,thereby. decreasing the capacity of the well.

In the Astrainer herein-after described there is a direct path of iowwhich is of advantage, irst in permitting development of the well bypumping and surging to increase its capacity; and second, in decreasingthe friction lossv of water passing through the strainer itself, therebyincreas-V ing the quantity of iiow.

`Since the strainer openings Icannot in such construction be closetogether, it is extremely important also that provision be made forvertical iiow of the water along the casing in smooth and closelyaligned passageways, as distinguished from strainers which haveseparatedl channelways which require tangential flow of the water toreach them before the vertical iow begins. In other words it is fully asdesirable that water reaching the outer surface of the strainer betweenopenings bep-rovided with the most direct possible channel tol suchopening and that the direction of flow be diverted a minimum amount, andthatfor such diversion an unobstructed channel be provided Which is notpossible where channels are spaced apart with intermediate fiat surfacesof considerable extent where flow is impeded not only by directionchange from radial, to tangential, then to radial and then to vertical,but is also prevented from making a direct tangential flow by the sandor gravel packing against the surface ofthe strainer.

With these facts before us, the objects ofour invention, are

First, 'to provide means for aligning and centering the units orsections and preventing displacement ofthe sections with reference toeach other; Second, to provide a maximum of bearing surface betweensections whereby crushing and destruction of the effectiveness j of thestrainer openings may not be caused by the weight of the superimposedsections;

Third, to provide as Afar as possible a straight line and direct path ofiow between the exterior and interior of the strainer;

Fourth, to provide as far as possible for unobstructed vertical flowalong the exterior of the strainer; and

Fifth, to generally improve the details of construction of suchstrainers. y

We accomplish these objects, first, by employing a male and femalejoint, preferably with inclined surfaces, which will align the rlngs asthej7 are being placed, center them 'directly one above the other, andhold them when in place against displacement.

Second, by making the male member ofthe joint slightly longer than thedepth of the female member and additionally employing lugs on thecontiguous portion of the male member to provide bearing surface betweensections and separate them rto provide openings between sections forinflow of water between sections.

Third, by providing contiguous, substantiallyV shaped, corrugationsvertically disposed on the exterior surface of the sections, whereby thechannels thus formed will be adjacent,'and whereby the gravel and largersand surrounding the strainer will bridge over the V shaped grooves andthereby create numerous vertical channels for the passage of the waterto the openings or passageways leading inward between the sections, andas will be more Vfully hereinafter set out in the drawings,specification and claims. to which reference is now made..

In the drawings:

Fig. 1 is a plan view of the sections.

Fig. 2 is a section on the line II--II of Fig. 1 showing a number ofsections in super-imposed relation.

Fig. 3 is a bottom view of the sections.

Fig. 4 is a section of the lower portion of a well with a number ofstrainer units in position in the well as they would appear when thewell is finally completed.

Fig. 5 is an enlarged fragmentary plan of a portion of a section of oneunit to show the detail of the vertical grooves and the gravel adjacentthereto.

Referring now to the drawings, in which the various parts are indicatedby numerals. 1 1s a strainer unlt of concrete in the form of an annularring ,having a vertically" milled or corrugated exterior surface 2 andpreferably a smooth cylindricalinnery surface 3. The bottom of each ofthese units is undercut preferably along an inclined surface 4, leavingthe outer portion an annular ring 5 projecting below'the remainingportion ofthe bottom,` and forming female portion of the joint. The topis complementary in form having the inner portion projecting upward toform the male portion of the joint, the outer surface 6 of thisprojection being so inclined that these -units will nest one upon theother. The upwardly projecting portion of the top of the unit ischannelled through along radial lines to form alternate channels 7 andprojecting lugs 8. 'Preferably some of these lugs, such as the lug 8Aare of larger size than the remaining lugs andfthe unit at such lugs`may be provided with vertical holes 9,

either through the lug or adjacent thereto,

through which cables or rods may be passed, r

should it be se desired. In forming these channels, it -is preferredthat they be cut below the genera-l surface of the top of the lunitasshown by the side lView 7A (Fig. 2), thus providing a downwardlyinclined channel for the entering water. The height of the lugs 8 isgreater than the height of the annular ring 5 so that a space 10 is leftbetween the units at the outer edge thereof which 'space provides acommunicating opening leading into the channels 7.

Extending radially beyond the lugs 8 are flat bosses 1l which have aheight equal to thel .desired space 10 and provide additional bearingsurface for the superimposed sections. These bosses may extend to theouter surface of the sections, but preferably eX- tend only as shown sothat the space 10 is anl uninterrupted one around the sections.

In Fig. 4 the lower end of a well with the strainer therein is shown.The hole or well 12 is larger than the outer diameter of the strainersections therein and the space therebetween is filled with gravel 13which acts to hold the surrounding sand away from the strainer.

In Fig. 5 the relation of the gravel 13 t the V shaped grooves of thecorrugated surface 2 is shown. In this view, the size of the gravel isshown much lsmaller in relation to the grooves than is normally thecase, yet the. bridging action by which the'grooves are leftuninterrupted is clearly shown. 14 is a supporting shoe preferably ofmetal on which the bottom strainer unit rests. These grooves are shown Vshaped. but lit will be readily understood that while we prefer to somake them` they are not necessarily of such shape but may be any form jextending entirely tical deviations from true vertical lines ma bepermitted if desired.

In use the superposed units or sections are placedin the well eachresting on and supported by the next lower unit, the outer portionsbeing spaced apart by the bosses 11 and the lugs 8 as-before described.The

strainer is then surrounded with gravell and such work of increasingfiow isdone as may I- be desired.

' We have confined this description to units madel of concrete but Wewish it distinctly understood that other materials such for instance asclap products, may bel used` if it be so desired.

Having now fully described our invention, what we claim and desire tosecure by Letters Patent in the United States is l. As a strainer unitfor a weil, an annular' member, having a female end, and a complementarymale end having the projecting portion of slightly greater depth thansaid female portion, said projecting portion being divided intoalternate lugs and channels and projecting bosses on said male end ofthickness equal to the difference in depth of said male and femaleportions extending radially outward from the base of said lugs towardbut not to the outer edge of said member. l l

2. As a strainer unit for a well, an annular member, having a femaleend, and a complementary male end having the 'projecting portion ofslightly greater depth than said female portion, said projecting portionbeing divided into alternate lugs and channels, and vertically disposedcontiguous corrugations, on the outer surface of said member, extendinginward from said surface a less distance than to said lugs., whereby theengaging surfaces of said lugs are left. intact. f

3. As a strainer unit fora well, ,an annular member, having a femaleend, and a complementary male end having' the projecting portion ofslightly greater depth than' said female portion, said projectingportion being divided into alternate lugs and channels, projectingbosses onsaid male end of thickness equal to the difference in depth ofsaid male and female portions, extending radially outward from the baseof said lugs, toward but not to the outer edge of said member, andvertically disposed contiguous corrugations, on the outer sur face ofsaid member, extending inward from said surface a less distance than tosaid bosses, whereby the supporting surfaces of said bosses are leftintact.

4. As a strainer unit for a well, an annular nzzember, having a femaleend` and a complementary' male end having the projecting portion ofslightly greater depth than sai-d female portion, said projectingportion being divided into alternate lugs and' channels, and projectingjbosses on said -maleend of thickness equal to the difference in depthof said male andlfemale `portions' extending radially outward from thebase o f'fsaid. lugs. v 5..A concrete well strainer comprising aplurality of superposed annular units, each unit having a male andfemale end, the female end of one Section engaging with the male\ end ofthe adjacent section, the projecting member ofy said male end being ofslightly greater length than the depth of said female end and beingdivided into alternate lugs and channels, whereby the outer surface ofadjacent sections will be spaced apartand channelways be provided inwardfrom the openings thus formed; said units having verticallydsposed Vshaped corrugations on the outer surface thereof, extending inward fromsaid surface a less distance than to said lugs, whereby the er1- gagingsurfaces of saidlugs are left intact. 6. A concrete Vwell strainercomprising a plurality of superposed annular units, each unit having amale and female end, the female end of one Sectiom engaging with themale end ofthe adjacent section, t-he projecting member ofsaid male endbeing of slightly greater length than the depth of said female endendbeing divided into alternate lugs and channels, whereby the outersurface of adjacent sections will be spaced' apart and channelways beprovided inward from the openings thus formed, and projecting bosses onsaid male end of thickness equal to thev difference in depth of saidmale and female portions, extending radially outward from the base ofsaid lugs toward but not to the outer edge -of said unit; said unitshaving vertically disposed contiguous V shaped grooves on the outersurface thereof, extending inward from said surface a less distance thanto said bosses.

7. A well strainer comprising a plurality of superposed. annular units,each having a male and a female end, the female end of lone unit beingengaged bythe male end of the adjacent unit, the male end of each unitbeing divided into alternate lugs and chan nels, and the outer faces ofsaid lugs, and

-the inner face of each female end, being bevelled correspondingly,whereby each ot' `said units is self-centered, due to engagement of oneof said beveled faces, upon its ends being joined with a co-acting endof .another uni 8. A well strainer comprising a plurality of superposedannular units, each having a male and a female end, the female end ofone unit being engaged by the male end of tbe adjacent unit, theprojecting portion of he male end of each unit being of slightly outerfaces of said lugs,

yrespondingly, whereby each of said units ie self-centered, due toengagementof said beveled faces, npon one of its ends being l0 joinedWith a co-acting end of another unit.

In testimony whereof We have hereunto set our names. I

JOSEPH P. LAVVLOR. JAMES I. SEAY.

